The phonograph, invented by Edison in 1877, was the first machine to
record the human voice.Edison’s vision
was for a business dictation machine.However, from the latter years of the 19th century to 1929
the phonograph became a medium for recorded music.

The recordings were cylindrical with
a spiral grove on the outside which functioned much like the disk records that
preceded compact discs. Unlike many 45s and 78s which were purely lateral
recordings,phonograph cylinders were
vertical recordings. That is, the stylus followed a vertical path over hills
and dales rather than the zig-zagpath
common on mono discs.Later stereo
records were to employ both systems in one groove; lateral and vertical. This last fact is significant in the
building of my own phonograph.

Cylinder recordings
are collectables which have their own dedicated following.They offer a view into the popular music
from the era of our great grandparents and are a valuable primary source for
many historians.

Cylinders came in a variety of sizes; two minute and four minute
duration,four inches to six inches
long, two and a quarter to five inches in diameter. All of these required a
different machine for playback.Specifically the two and four minute cylinders have a different groove
pitch; one hundred grooves per inch for the two minute, and two hundred for the
four minute.

There is a modern machine currently available on the market which is
capable of playing all the various cylinder formats.It weighs over 100 lbs and costs sixteen thousand dollars and
change. For this reason I decided to build my own and being a licensed
machinist I decided to call it:“The
Machinist’s Phonograph.”

Plan View

The Machinist’s Phonograph plays both two minute and four minute
cylinders. To do so, the lead screw drive ratios can be altered by moving the
belt to the set of adjacent pulleys.The sizes of the pulleys were calculated to maintain both ratios (1:5
and 1:10) while at the same time using the same beltThe beltis made from an
elastic material and thus allows some stretch.Because I used a flat belt with crowned pulleys from the mandrel spigot
to the lead screw, the inaccuracies due to belt slippage or other machining
factors are compensated by the tone arm whichhas lateral pivot.However, this
is not noticeable as the tone arm has good linear tracking on both two and four
minute cylinders.

End Elevations

(showing two cylinder sizes)

With the use of different sleeves the tone arm can be raised upon its
mount to accommodate pathé intermediate and 5 inch cylinders. Different
diameter mandrels can also be easily attached to the drive spigot. The lead
screw has6½ inches of usable travel so
it will also accommodate the longer 6 inch Columbia cylinders.

The current tone arm cartridge holds
BSR 78 sapphire stylus from a stereo turntable.Eventually this will be replaced by a Stanton cartridge.The treble channel normally wired for lateral
recordings has been re wired for vertical.This allows a clear signal to both speakers.For 2 minute wax cylinders a glass ball stylus is used (the
design of which is courtesy of Mr Lomas. see: phonograph makers’ pages

The knob at the front controls the speed of the AC motor. Its original
purpose was a wall mounted switch designed for a domestic fan.Speed selection is done by ear.Though a strobe light is a possible future
addition.

Nylon with Steel
Axle.

The arrangement
below allows ill fitting cylinders to be played without the need for reaming.
The taper is: ⅛”ø over 4” length.

Nylon was used for the pulleys, the mandrel, the
tone arm, cartridge holder, and carriage. The rest of the machine is made of aluminium.
With the exception of the lead screw, the carriage rail and the spigot upon
which the mandrel is mounted, these are steel. The spigot runs in plain oilite
bushes pressed into reamed holes in the two vertical aluminium
uprights. The belts are vacuum cleaner belts. The box is wood. The
motor is an AC fan motor. There is a bit of a whirrr from the machine but
it is completely drowned out by the recorded sound.